我国村镇生活垃圾可燃组分基本特征及其时空差异

为了解我国村镇生活垃圾组成特征及采取焚烧处置的可行性,本研究在2015年的春夏秋冬4个季节,对我国12个省份共72个村镇生活垃圾产生源进行采样调查,分析了垃圾全组分和可燃组分的质量分数、含水率以及垃圾热值等参数,进行了地域、季节以及村与镇之间差异分析.结果表明,我国村镇生活垃圾可燃组分质量分数(湿基)由高到低的顺序为:厨余类(13%~53%)橡塑类(10%~18%)纸类(10%~15%)木竹类(0~10%)织物类(0~8%).相同行政区域内村与镇之间生活垃圾组分差异较小,南方村镇生活垃圾全组分的平均含水率大于北方,全国村镇生活垃圾平均含水率为40.1%左右.我国北方生活垃圾热值在4个季节均有81%的村镇超过3 500 k J·kg~(-1),而南方村镇生活垃圾在春、夏、秋、冬这4个季节满足这一条件的村镇分别占44%、50%、61%、72%.垃圾经分选后热值得到提高,但南方村镇春季生活垃圾可燃组分热值仍然偏低,南方其它季节56%以上的村镇和北方全年所有村镇的生活垃圾均能满足焚烧处置的热值要求,故对我国北方农村生活垃圾进行焚烧处置是可行的,而南方村镇生活垃圾需加强前处理工艺.     

哈尔滨市采暖与非采暖期大气颗粒物污染特性研究

为了研究采暖对哈尔滨市大气颗粒物环境特征的影响,分别在采暖前、采暖期和采暖后采集TSP、PM10和PM2.5.分析了3种粒径颗粒物在采暖期和非采暖期的浓度变化特征以及粒径分布特征,并做了颗粒物的化学成分分析,包括20种无机元素和两种碳成分.结果表明:TSP和PM10在12月、1月、3月和4月均超标,而在非采暖期均达到国...     

含金属元素化合物和压力对工业污泥燃烧特性的影响

为了更好地利用工业污泥,有必要对它的燃烧特性进行研究,因而利用热重法研究了由3种典型的工业污泥按质量比1∶1∶1混合后的多组分试样在掺混含不同金属元素混合物、不同升温速率以及加压下的燃烧特性.实验结果表明,含金属元素化合物对污泥的燃烧能起到一定的催化作用,有助于改善工业污泥的着火性能,提高工业污泥的燃烧放热量和燃尽水平.含不同金属元素化合物对于污泥燃烧的催化机制和作用有所差异.实验中各种含金属元素化合物促进污泥燃烧过程的作用次序由大到小依次为:K2CO3、NaCl、Al2O3.随着压力的增大,污泥试样燃烧反应区间向低温区移动,各特征温度均呈下降趋势,综合燃烧特性指数有所提高;而随着升温速率的增大,污泥试样燃烧反应区间向高温区移动,各特征温度均有所增大,但综合燃烧特性愈好,对污泥燃烧越有利.     

The effect of ventilation on spontaneous heating of coal

Ventilation plays an important role in the spontaneous heating of coal in an underground coal mine. If the ventilation rate is too high, heat is carried away by convection. If the ventilation rate is too low, the reaction rate becomes oxygen-limited. The effect of ventilation on the spontaneous heating of coal was investigated in an isothermal oven in this study. Experiments were conducted on three U.S. coal samples with ventilation rates ranging from 100 to 500 cm³/min. Experiments under ventilation were conducted to determine the critical ambient temperature, which is the minimum oven temperature required for a coal sample to achieve thermal runaway. Spontaneous heating tests were then conducted at various ventilation rates at the critical ambient temperature and the results were compared with spontaneous heating tests without ventilation. It was found that there is an optimum ventilation flow to produce the maximum rate of temperature rise at the critical ambient temperature. When the coal sample particle size was increased, a higher critical ambient temperature was required. The results in this study have application in the prevention of spontaneous combustion in underground coal mines.     

电阻加热修复佳乐麝香污染土壤的工艺优化

佳乐麝香(Galaxolide,HHCB)是土壤中的一种新兴的半挥发性有机污染物,具有较高的毒性,需修复治理。电阻加热技术(electrical resistance heating,ERH)因加热均匀、效果好,逐渐被应用于有机污染土壤修复工程。采用自主研制的电阻加热装置,研究了加热过程中电场强度、土壤含水率和土壤粒径等因素对土壤HHCB去除效果的影响,并采用响应面法对工艺参数进行了优化。结果表明,土壤 HHCB去除率随电场强度和含水率的增大先增加后减小,随土壤粒径的增大而增大;在土壤含水率为40%、土壤粒径1~2 mm和电场强度12 V·cm⁻¹的条件下,加热6 h,HHCB去除效果最好,去除率达到了81.35%。通过响应曲面模拟优化得到的最佳工艺参数条件为,含水率39.07%、土壤粒径2.92 mm、电场强度12.64 V·cm⁻¹,在此条件下土壤HHCB的去除率为86.43%;在本实验条件下,3个因素对土壤HHCB去除率的影响为：含水率>土壤粒径>电场强度。本研究结果可为多环麝香污染土壤的修复提供参考。     

Transformations in carbon and nitrogen-forms in peat subjected to progressive thermal stress as revealed by analytical pyrolysis

To study the characteristic N-forms of humic-type materials, samples of sapric peat from Galicia (northern Spain) were heated at 350 °C for 60, 90, 120, 150 and 180 s, and studied by Curie-point Py-GC/MS, solid-state CPMAS ¹³C-NMR and ¹⁵N-NMR spectroscopies. NMR analysis of the peat samples in the progressive heating stages showed the concentration of heterocyclic N-forms, the maximum structural transition amide-to-heterocyclic forms being observed in samples heated for 120 s (56% heterocyclic N and 34% aromatic C). Under more drastic conditions all N-forms were depleted. Correlation between spectroscopic and pyrolytic data betrayed specific pyrolytic markers for the different N-forms. The intensity of the ¹⁵N-NMR amide peak tended to be positively correlated to the yield of indoles, imidazoles and pyrazoles, and negatively correlated to those of benzonitriles and pyrazines. Analytical pyrolysis also showed a progressive enrichment in lipids and alkyl macromolecules with increasing heating intensity, and a decrease in lignin-derived, polysaccharide-derived and N-containing compounds. The relative abundance of non-methoxyphenolic aromatic compounds did not change. The N-compounds in peat samples unheated or heated for 60–90 s released methylpyrazole, dimethylpyrroline, methyldiphenylindole and pyrazole, whereas peat samples heated for 120 s mainly yielded methylpyrazine and methyldiphenylindole. Dimethylpyrroline and pyrazine prevailed in samples heated for 150 s, whereas samples heated for 180 s yielded mainly pyrrole. Pyrolysis data presented low possibilities for forecasting the extent of the O-alkyl domain, but reflected quantitatively the transformations in the lignin-like moiety. Both techniques coincide in pointing out the accumulation of a recalcitrant alkyl domain possibly derived from abiotic condensations or inherited lipid biomacromolecules.     

低温供热堆选址阶段的环境影响评价与分析

根据低温供热堆选址阶段环境影响评价的要求,结合工程具体设计方案,对低温供热堆在正常运行和事故工况下可能造成的环境影响进行分析、预测与评价,以作为审管当局决策的重要依据.低温供热堆在正常运行状态时,放射性气载流出物在大气中迁移和扩散及对公众的辐射剂量估算采用的是IAEA安全系列19号报告中给出的筛选模式(稀释模式);事故...     

周转时间的延长对焦炉加热的影响及调整

周转时间的延长引起2#焦炉加热系统中温度、压力的改变,使现有的加热制度不能适应焦炉生产的需求.为制订合适的加热制度,通过对影响2#焦炉加热制度的各项因素的分析,确定了影响加热制度的主要原因,即标准火道(flame path)冷却温度的不合适和焦炉煤气(coal oven gas)横管两端压力低.在经过多次试验的基础上,对加热制度进行调整,制定了合适的加热制度,为2#焦炉在周转时间延长后的正常生产提供了有力的保障.     

新型固硫节煤剂在供热锅炉系统中的应用

长庆油田矿区服务事业部各生活小区锅炉90%的能源用于小区采暖供热,锅炉供热能耗大,效率低。为降低供热能耗,2012年1月对庆城基地锅炉系统中的SZL14--1.0/95/70型号锅炉使用固硫节煤剂的应用效果进行了现场试验对比。试验证明:通过添加新型固硫节煤剂能改善炉膛燃烧氛围、促进燃烧完全,降低炉渣含碳量,提高热效率7%,节煤率12%。同时,固硫效果明显,烟尘排放CO、SO2明显减少。     

润滑油废白土的热解处理

以润滑油废白土为原料,利用电热解法,研究了热解终温、加热速率和CaO添加量对热解产物的影响。实验结果表明:热解终温对热解产物的影响最为显著。随着热解终温的升高,不凝气产量和产油率均迅速增加。当热解终温达到600℃时,其增加的速率逐渐缓慢增大。当控制热解终温为800℃、加热速率为16℃/min、CaO添加量为0.5%时,富氢气体产量为189.2 L/kg,气体中主要成分为H2和CH4,其含量分别为27.97%和41.64%;热解残渣含油率和重金属溶出物均低于标准规定值,热解油产率为10.98%,回收率为38.94%,其主要成分为汽油、柴油和重油3部分组成,分别含19.13%、31.35%和49.52%。